Tic Toe Toe or O's & X's
A great game to play with or without the usual O's & X's rules!
Depending on the age of your children let them pay with the concept of one counter per square - see if they can pick out the sequence lines without the competitive edge of winning ..

For older children and mark making, this activity sheet from Inky Bear's page is ideal for multiple print outs O's & X's activity sheet
 
The following pieces are for a 'counter ' playing game as opposed to the pen & paper sheet above.